Extreme temperature and airway dehydration: current understanding and integrative insights into respiratory vulnerability.

Abstract

Introduction: Climate change has significantly increased the frequency and intensity of extreme temperature events, posing growing threats to respiratory health. Among the underlying mechanisms, airway dehydration is a critical yet underrecognized pathway that disrupts the airway surface liquid (ASL), which is essential for mucociliary clearance, epithelial integrity, and immune defense.

Areas covered: This article examines evidence linking airway dehydration to respiratory disease during temperature extremes. We discuss how hot, dry air and cold, low-humidity conditions disrupt airway hydration balance, leading to impaired mucociliary clearance and increased susceptibility to infection and inflammation. The review summarizes the impacts of airway dehydration on vulnerable populations, including individuals with pre-existing respiratory conditions (asthma, allergic rhinitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis), children, older adults, outdoor workers, and socioeconomically disadvantaged groups.

Expert opinion: Airway dehydration represents a unifying mechanism linking climate extremes to respiratory vulnerability but remains underrepresented in clinical practice and public health strategies. We advocate for greater recognition of airway hydration in disease prevention, development of practical measurement tools, and targeted interventions for at-risk populations. Emphasizing airway dehydration as a key mediator offers opportunities to improve clinical management and develop effective climate adaptation strategies for respiratory health protection.